The cubic boron nitride has hardness next to the diamond and excellent thermal conductivity. In addition, the cubic boron nitride has a characteristic that it has low affinity with iron. A cubic boron nitride sintered body comprising cubic boron nitride, and a binder phase of a metal(s) and/or ceramics has been applied to a cutting tool and a wear resistant tool, etc.
For example, as a prior art of the cubic boron nitride sintered body, there is a cubic boron nitride sintered body comprising cubic boron nitride and at least α-Al2O3 and a Zr compound as a binder phase (see Patent Document 1.).